Electronic device with electrode and its manufacture

ABSTRACT

A method of manufacturing an electronic device includes the steps of: (a) preparing a (001) oriented ReO 3  layer; and (b) forming a (001) oriented oxide ferroelectric layer having a perovskite structure on the ReO 3  layer. Preferably, the step (a) includes the steps of: (a-1) preparing a (001) oriented MgO layer; and (a-2) forming a (001) oriented ReO 3  layer on the MgO layer. An electronic device capable of obtaining a ferroelectric layer of a large polarization and a method of manufacturing the same are provided.

CROSS REFERENCE TO RELATED APPLICATION

[0001] This invention is based on and claims priority of Japanese patentapplication 2001-329688, filed on Oct. 26, 2001, the whole contents ofwhich are incorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to an electronic device having aferroelectric layer and a method of manufacturing the same, moreparticularly to an electronic device having a ferroelectric layeroriented crystallographically and a method of manufacturing the same.

[0004] 2. Description of the Related Art

[0005] A semiconductor memory, in which one memory cell is constitutedof one transistor and one capacitor, has been widely known. A capacitorof a dynamic random access memory (DRAM) has a capacitor dielectriclayer formed of a paraelectric material. Electric charges stored in thecapacitor gradually decrease therefrom due to their leak even when thetransistor is turned off. Accordingly, when a voltage applied to thememory cell is removed, information stored therein decreases anddisappears before long.

[0006] A memory capable of retaining information stored therein evenafter power is cut off is called a non-volatile memory. As a kind of thenon-volatile memory, a one-transistor/one-capacitor type memory, acapacitor dielectric layer of which is formed of a ferroelectricmaterial, has been known, which is called a ferroelectric random accessmemory (FeRAM).

[0007] The FeRAM utilizes residual polarization of the ferroelectricmaterial as information stored therein. The FeRAM controls a polarity ofa voltage applied between a pair of electrodes of the ferroelectriccapacitor, thus controlling the direction of the residual polarization.Assuming that one polarization direction be “1” and the other be “0”,binary information can be stored. Since the residual polarizationremains in the ferroelectric capacitor even after the applied voltage isremoved therefrom, the non-volatile memory can be realized. In thenon-volatile memory, information can be rewritten by a sufficient numberof times, that is, 10¹⁰ to 10¹² times. The non-volatile memory also hasa rewriting speed of an order of several ten nanoseconds and offers ahigh-speed operability.

[0008] As ferroelectric materials, lead-based oxide ferroelectricmaterials having a perovskite structure and bismuth-based oxideferroelectric materials having a bismuth-layered structure have beenknown. Typical examples of the lead-based ferroelectric materials arePbZr_(x)Ti_(1-x)O₃ (PZT), Pb_(y)La_(1-y)Zr_(x)Ti_(1-x)O₃ (PLZT) and thelike. A typical example of the bismuth-based oxide ferroelectricmaterials is SrBi₂Ta₂O₉ (BST).

[0009] The ferroelectric capacitor offers a higher charge retentioncapability as the polarization of the ferroelectric material is greater,and can retain the electric potential with less capacitance.Specifically, the FeRAM can be fabricated with high integration.Furthermore, as the polarization of the ferroelectric material isgreater, the polarization directions can be differentiated more clearlyeven at a low reading-out voltage, thus enabling the ferroelectricmemory to be driven at a low voltage.

[0010] It is effective to arrange orientations of ferroelectric crystalsuniformly in order to increase a polarization amount of theferroelectric material. For example, on pages 382 to 388 of “Journal ofApplied Physics” 1991, vol. 70, No. 1, disclosed is a technology ofobtaining a (111)-oriented ferroelectric thin film, in which metal thinfilms formed of metals such as platinum (Pt) and iridium (Ir) aredeposited at 500° C. to obtain a (111)-oriented metal thin film, and aferroelectric thin film such as PZT is deposited on this metal thin filmat a room temperature, followed by heating of the depositedferroelectric thin film to a range from 650° C. to 700° C. However, themaximum temperature permitted for a manufacturing process of the FeRAMis usually 620° C.

[0011] The ferroelectric material such as PZT having a tetragonal simpleperovskite structure has a polarization axis along the c axis <001>.Accordingly, the polarization amount becomes maximum when theferroelectric layer is approximately oriented along a (001) plane(hereinafter, referred to as (001)-oriented). When the ferroelectriclayer is (111)-oriented, a component of the polarization produced in<001> direction is only about {fraction (1/1.73)} in <111> directionthat is a thickness direction of the ferroelectric layer. Although thepolarization can be increased by aligning orientation, it is impossibleto increase the polarization to the maximum.

SUMMARY OF THE INVENTION

[0012] An object of the present invention is to provide an electronicdevice capable of obtaining a ferroelectric layer having a largepolarization amount and a method of manufacturing the same.

[0013] Another object of the present invention is to provide anelectronic device provided with a (001)-oriented ferroelectric layer anda method of manufacturing the same.

[0014] Still another object of the present invention is to provide anelectronic device provided with a ferroelectric capacitor having a ReO₃layer as at least one of electrodes and a method of manufacturing thesame.

[0015] According to one aspect of the present invention, there isprovided an electronic device including: a ReO₃ layer having a (001)orientation; and an oxide ferroelectric layer having a perovskitestructure, the oxide ferroelectric layer being formed on the ReO₃ layerand having a (001) orientation.

[0016] According to another aspect of the present invention, there isprovided a method of manufacturing an electronic device, including thesteps of: preparing a ReO₃ layer having a (001) orientation; and formingan oxide ferroelectric layer having a perovskite structure on the ReO₃layer, the oxide ferroelectric layer having a (001) orientation.

[0017] A (001)-oriented MgO layer is preferably used as an underlyinglayer of the ReO₃ layer.

[0018] Lattice matching can be made for the (001)-oriented ReO₃ layerand the (001)-oriented oxide ferroelectric layer having a perovskitestructure; accordingly, the (001)-oriented oxide ferroelectric layerhaving a perovskite structure can be formed on the (001)-oriented ReO₃layer.

[0019] The MgO layer can be easily (001)-oriented. The lattice matchingcan be made for the (001)-oriented MgO layer and the (001)-oriented ReO₃layer. Hence, the (001)-oriented ReO₃ layer and the (001)-oriented oxideferroelectric layer having a perovskite structure can be formed on the(001)-oriented MgO layer sequentially.

[0020] The term “ReO₃” used herein includes ReO₃ to which metal otherthan Re is added, for example, for controlling a lattice constantthereof.

[0021] In such a manner as described above, it is possible to form aferroelectric capacitor capable of realizing greater polarization.

BRIEF DESCRIPTION OF THE DRAWINGS

[0022]FIG. 1A is a schematic cross-sectional view of an electronicdevice; FIG. 1B is a schematic block diagram showing a constitution of ametalorganic chemical vapor deposition (MOCVD) apparatus; FIG. 1C is aschematic cross-sectional view showing an upper electrode of theelectronic device when a stacked structure is adopted therefor; and FIG.1D is a schematic cross-sectional view of the electronic device when asingle crystal MgO layer is used therefor, all of which are made forillustrating embodiments of the present invention.

[0023]FIGS. 2A and 2B are structural views showing chemical formulae ofMg(DPM)₂ and i-PrO.

[0024]FIGS. 3A and 3B are cross-sectional views of constitutionalexamples of an electronic device having a ferroelectric capacitoraccording to embodiments of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Hereinafter, description will be made on embodiments of thepresent invention with reference to the drawings.

[0026]FIG. 1A shows a structure of a ferroelectric capacitor accordingto a fundamental embodiment of the present invention. A silicon oxidelayer 11 is formed on a Si substrate 10. The silicon oxide layer 11 canbe formed by thermal oxidation of silicon, chemical vapor deposition(CVD) or the like. The silicon oxide layer 11 may be formed by othermethods. The silicon oxide layer 11 has an amorphous phase. A(001)-oriented MgO layer 12 is formed on the silicon oxide layer 11, a(001)-oriented ReO₃ layer 13 is formed on the MgO layer 12, and a(001)-oriented PZT layer 14 is formed on the ReO₃ layer 13.

[0027] The (001)-oriented MgO layer 12, the (001)-oriented ReO₃ layer 13on the MgO layer 12 and the (001)-oriented PZT layer 14 on the ReO₃layer 13, the PZT layer 14 being a ferroelectric layer having aperovskite structure, can be deposited by metalorganic chemical vapordeposition (MOCVD) using a metalorganic (MO) material.

[0028]FIG. 1B schematically shows a structure of an apparatus fordepositing a film by MOCVD. A liquid container 21-1 contains ametalorganic material solution used for deposition. Pressurized He gasis fed to the liquid container 21-1 from a pipe opened to a space on thesolution, thus enabling the solution to be supplied to another pipe 22-1deeply intruded into the solution. A flow rate of the supplied solutionis controlled by a mass flow controller (MFC) 24-1, and the solution issupplied to a vaporizer 27-1 through a pipe 25-1.

[0029] A carrier gas pipe 26 is connected to the vaporizer 27-1. Theliquid raw material solution supplied to the vaporizer 27-1 togetherwith carrier gas N₂ is vaporized by the vaporizer 27-1 and supplied to apipe 28-1.

[0030] A liquid container 21-2, a pipe 22-2, a mass flow controller24-2, a pipe 25-2, a vaporizer 27-2 and a pipe 28-2 have similarstructures as those of the liquid container 21-1, the pipe 22-1, themass flow controller 24-1, the pipe 25-1, the vaporizer 27-1 and thepipe 28-1, which are described above, respectively. Furthermore, anynumber of similar raw material supply systems may be provided.

[0031] The vaporizer 27-1 may be connected with other liquid rawmaterial supply systems having similar structures as those of the liquidcontainer 21-1, the pipe 22-1, the mass flow controller 24-1 and thepipe 25-1. Other vaporizers can also be provided with any number of theliquid raw material supply systems.

[0032] A reaction chamber 30 has raw material pipes such as a gas pipe29 and the liquid raw material pipes 28-1, 28-2 . . . , and can supplyraw material gas from a showerhead 32. A susceptor 34 capable ofcontrolling a temperature thereof is disposed at a lower portion of thereaction chamber 30, and a substrate 35 composed of, for example, asilicon substrate provided with a silicon oxide layer is disposed on thesusceptor 34.

[0033] In the above description, an example is shown, in which the rawmaterial supply systems are provided in plural; however, a single systemmay be employed. Moreover, an example of a single reaction chamber isshown; however, a plurality of the reaction chambers may be provided.

[0034] With regard to a metalorganic material contained in the liquidcontainers, for example, as a Mg raw material, a solution obtained bydissolving Mg(DPM)₂ (where DPM is dipivaloilmethanate) in thetetrahydrofuran (THF) can be used.

[0035]FIG. 2A is a chemical formula showing a chemical structure ofMg(DPM)₂. Dipivaloilmethanate (DPM) is bonded at each side of a Mg atom.DPM is monovalent, and n pieces of DPMs can be bonded to an n-valentatom.

[0036] As a Re material, a solution obtained by dissolving Re(DPM)₂ inTHF can be used. A chemical formula of Re(DPM)₂ is equivalent to thatobtained by replacing Mg with Re in the chemical formula shown in FIG.2A.

[0037] As a Pb material, a solution obtained by dissolving Pb(DPM)₂ inTHF can be used. A structure of Pb(DPM)₂ is equivalent to that obtainedby replacing Mg with Pb in the structure shown in FIG. 2A.

[0038] As a Zr material, a solution obtained by dissolving Zr(DPM)₄ inTHF can be used. Zr(DPM)₄ has a structure where four DPMs are bondedaround one Zr atom.

[0039] As a Ti material, a solution obtained by dissolving Ti(i-PrO)₂(DPM)₂ (where i-PrO is an iso-proxy group) in THF can be used. Astructure of Ti (i-PrO)₂(DPM)₂ is equivalent to that obtained byreplacing Mg with Ti in the structure shown in FIG. 2A and by bondingtwo iso-proxy groups shown in FIG. 2B to Ti. Note that the metalorganic(MO) material is not limited to these examples.

[0040] In order to deposit the MgO layer 12 shown in FIG. 1A,pressurized helium (He) gas is fed to the liquid containers 21containing the solution obtained by dissolving Mg(DPM)₂ in THF, and thesolution is made to pass through the vaporizers 27 heated at 260° C.,vaporized, and loaded on the carrier gas N₂.

[0041] The Mg raw material, for which N₂ is used as carrier gas, is fedthrough the pipes 28 to the showerhead 32, and supplied to the siliconoxide film on the substrate 35 together with O₂ gas supplied from thepipe 29. The silicon oxide film is heated to 560° C., decomposes thesupplied metalorganic gas, and combines the decomposed gas with oxygen,thus depositing a (001)-oriented MgO layer. A thickness of the(001)-oriented MgO layer is set, for example, in a range from 50 to 100nm.

[0042] Deposition temperature is not limited to 560° C. Preferably,deposition is carried out with substrate temperature of 620° C. orlower. Accordingly, a step of the deposition can be harmonized withother manufacturing steps for the FeRAM device.

[0043] Next, description will be made for the case of depositing theReO₃ layer 13 on the (001)-oriented MgO layer 12. In order to depositthe ReO₃ layer 13, the liquid raw material obtained by dissolvingRe(DPM)₂ in THF, which is contained in the liquid containers 21, isused, and the metalorganic material loaded on the carrier gas is fed tothe showerhead 32 in the same manner as the above-described process. Tothe showerhead 32, O₂ gas, mixed gas of O₂ gas and N₂ gas or the like issimultaneously supplied.

[0044] The substrate 35 having the (001)-oriented MgO layer 12 formedthereon is kept at a constant temperature of 560° C. by means of thesusceptor 34. The raw material gas is supplied onto the (001)-orientedMgO layer 12 kept at 560° C., whereby the (001)-oriented ReO₃ layer 13is deposited. A thickness of the (001)-oriented ReO₃ layer 13 is set,for example, in a range from 20 to 50 nm.

[0045] After the (001)-oriented ReO₃ layer 13 is deposited, the PZTlayer 14 is deposited thereon. For the PZT, as a Pb raw material, thesolution obtained by dissolving Pb(DPM)₂ in THF is used; as a Zr rawmaterial, the solution obtained by dissolving Zr(DPM)₄ in THF is used;and as a Ti raw material, the solution obtained by dissolving Ti(i-PrO)₂(DPM)₂ in THF is used. Pressurized helium gas is fed to threeliquid containers containing these liquid raw materials, and the liquidraw materials are vaporized by one or three vaporizers and supplied tothe showerhead 32.

[0046] The substrate temperature is kept at 560° C., and Pb(DPM)₂ gas,Zr(DPM)₄ gas, Ti(i-PrO)₂(DPM)₂ gas and oxygen are simultaneously blownonto the substrate, thus the Pb(Zr, Ti)O₃ (PZT) layer 14 is deposited onthe (001)-oriented ReO₃ layer 13. The deposited PZT layer 14 has also(001) orientation. A thickness of the (001)-oriented PZT layer 14 isset, for example, in a range from 80 to 150 nm.

[0047] As described above, an MgO layer is deposited on an amorphoussilicon oxide layer 11 by MOCVD, to obtain a (001)-oriented MgO layer12. On the (001)-oriented MgO layer 12, there can be deposited a ReO₃layer 13, which is (001)-oriented in accordance with the orientation ofthe underlying layer, that is, the MgO layer 12. Furthermore, on the(001)-oriented ReO₃ layer 13, there can be deposited the PZT layer 14,which is (001)-oriented in accordance with the orientation of theunderlying layers, that is, the MgO layer 12 and the ReO₃ layer 13.

[0048] An upper electrode 15 is formed on the PZT layer 14. The upperelectrode 15 is not required to be (001)-oriented and can be formed ofan electrode material publicly known hitherto. For example, an IrO₂layer is deposited by MOCVD. In this case, as an Ir raw material, asolution obtained by dissolving Ir(DPM)₃ in THF is used. Process forvaporizing the material is similar as that described above. Thesubstrate temperature is kept at 560° C., and Ir(DPM)₃ gas and oxygenare simultaneously blown thereonto, thus enabling the upper electrode 15made of IrO₂, which is also referred to as an IrO₂ layer, to bedeposited on the PZT layer 14. A thickness of the IrO₂ layer 15 is set,for example, in a range from 100 to 150 nm.

[0049] Description has been made for the case of forming the upperelectrode 15 of an IrO₂ layer; however, various materials can be usedfor the upper electrode irrespective of the orientation of theferroelectric layer.

[0050] As shown in FIG. 1C, for the upper electrode, a stacked layer 15obtained by stacking an IrO₂ layer 15-1 and a SrRuO₃ layer 15-2 may beused. Deposition methods other than MOCVD may also be used.

[0051] For example, the IrO₂ layer 15-1 can be deposited by sputteringusing an IrO₂ target. In this case, the substrate is kept at a roomtemperature, and the target is sputtered by use of work gas Ar at avacuum degree of 3×10⁻⁴ Torr, thus the IrO₂ layer 15-1 is deposited. Athickness of the IrO₂ layer 15-1 is set, for example, in a range from100 to 150 nm.

[0052] The SrRuO₃ layer 15-2 to be deposited on the IrO₂ layer 15-1 canalso be deposited by sputtering. SrRuO₃ is used as a target, thesubstrate is kept at a room temperature, the vacuum degree is set at3×10⁻⁴ Torr, and Ar is used as work gas. Under the above-describedconditions, the target is sputtered, and thus the SrRuO₃ layer 15-2 isdeposited. A thickness of the SrRuO₃ layer 15-2 is set, for example, ina range from 10 to 30 nm.

[0053] Description has been made above for the case of using PZT as aferroelectric material; however, other oxide ferroelectric materialshaving a perovskite structure can be employed. For example,Pb_(y)La_(1-y)Zr_(x)Ti_(1-x)O₃ (PLZT),Pb_(1-a-b-c)La_(a)Sr_(b)Ca_(c)Zr_(1-x)Ti_(x)O₃ (PLSCZT) and the like canbe used.

[0054] Moreover, description has been made for the case of using only O₂gas as a kind of gas. However, mixed gas of O₂ and other gas, forexample, O₂/N₂, O₂/Ar, O₂/He and O₂/N₂O, can also be used.

[0055] ReO₃ added with a small amount of other metal shows an electricalresistivity of an order of 10⁻⁶ Ω·m at 300° K. A metal layer used as anelectrode can be utilized effectively as long as an electricalresistivity thereof is 10⁻⁵ Ω·m or less. Accordingly, ReO₃ added withthe other metal (metal impurities) can be utilized effectively as suchan electrode of the ferroelectric capacitor.

[0056] Note that the MgO layer is deposited on the amorphous siliconoxide layer 11, thus forming the (001)-oriented MgO layer 12; however,it will be obvious that a (001) plane of single crystal MgO can be usedin place of the deposited MgO layer.

[0057]FIG. 1D shows the case where a ReO₃ layer 13 and a ferroelectriclayer 14 having a perovskite structure are epitaxially grown in thisorder on a single crystal MgO layer 12 having a (001) plane, and then anupper electrode 15 is formed on the ferroelectric layer 14.

[0058] Furthermore, it will be possible to deposit the (001)-orientedMgO layer 12, ReO₃ layer 13 and ferroelectric layer 14 by, in place ofCVD using the metalorganic (MO) raw materials, CVD using other rawmaterials. Similarly, it will be possible to deposit the above(001)-oriented layers by sputtering.

[0059] The ferroelectric layer 14 is (001)-oriented, thus enabling thepolarization caused by application of the voltage to be aligned to adirection perpendicular to the electrode surface. Therefore, it is madepossible to utilize the polarization of the ferroelectric layer mosteffectively.

[0060]FIGS. 3A and 3B show constitutional examples of electronicdevices, each using the ferroelectric capacitor as described above.

[0061]FIG. 3A shows an example where electrodes are taken out of upperand lower surfaces of a ferroelectric capacitor. An element isolationregion 40 is formed on a surface of a Si substrate 10 by shallow trenchisolation (STI). Two MOS transistors are formed in an active regiondefined by the element isolation region 40. The two MOS transistors haveone source/drain region 46 as a common region and other source/drainregions 45 on both sides thereof, which are connected with theferroelectric capacitors, respectively.

[0062] On a channel region between the source/drain regions, is disposedan insulated gate electrode formed of a gate insulating film 41, apolycrystalline gate electrode 42 and a silicide gate electrode 43. Aside spacer 44 is formed on a sidewall of the insulated gate electrode.An amorphous insulating layer 11 made of silicon oxide or the like isformed over surfaces where the semiconductor devices are formed.Furthermore, a (001)-oriented MgO layer 12 is formed on a surface of theamorphous insulating layer 11.

[0063] In order to form an extraction electrode for each of theboth-side source/drain regions 45, a contact hole is formed through theMgO layer 12 and the amorphous insulating layer 11. An extraction plugcomposed of, for example, barrier metal 48 and a tungsten (W) plug 49 isformed in the contact hole. Then, unnecessary electrode layers on theMgO layer 12 are removed by, for example, chemical mechanical polishing(CMP). Subsequently, on the MgO layer 12, is formed a ferroelectriccapacitor composed of the lower ReO₃ layer 13, the ferroelectric layer14 having a perovskite structure 14 and the upper electrode 15.

[0064] The MgO layer 12 is (001)-oriented, thus making it possible toform the (001)-oriented lower ReO₃ layer 13 and the (001)-orientedferroelectric layer 14 having a perovskite structure.

[0065] After forming the ferroelectric capacitor, an insulating layer 50made of silicon oxide or the like is deposited to cover a surfacethereof. Moreover, a contact hole is formed through the insulating layer50, and then a barrier metal layer 51 and a metal conductive layer 52made of W or the like are buried in the contact hole, thus theextraction electrode is formed. After forming the extraction electrode,unnecessary electrode layers on the insulating layer 50 are removed, andupper wirings 54 and 55 are formed. Surfaces of the upper wirings 54 and55 are covered with an insulating layer 60.

[0066]FIG. 3B shows a constitution, in which two electrodes are takenout of the upper surface of the ferroelectric capacitor. An elementisolation region 40 of silicon oxide formed by local oxidation ofsilicon (LOCOS) is formed on the surface of the Si substrate 10. One MOStransistor is formed in an active region defined by the elementisolation region 40.

[0067] On a channel region, is disposed an insulated gate electrodeformed of a gate insulating film 41, a polycrystalline gate electrode 42and a polycrystalline silicide gate electrode 43. A side spacer 44 isformed on a sidewall of the insulated gate electrode. Source/drainregions 45 and 46 are formed on both sides of the gate electrode by ionimplantation and the like.

[0068] An amorphous insulating layer 48 made of silicon oxide or thelike is formed to cover the MOS transistor. Plugs 49 for deriving thesource/drain regions 45 and 46 are formed. A silicon nitride layer 59,for example, having an amorphous phase is formed on a surface of theamorphous insulating layer 48 through which the plugs 49 are formed,thus an oxygen shielding layer is formed.

[0069] On the amorphous silicon nitride layer 59, a (001)-oriented MgOlayer 12 is formed. It is conceivable that the (001)-oriented MgO layer12 can be deposited as long as its underlying layer is amorphous. On the(001)-oriented MgO layer 12, is formed a ferroelectric capacitorcomposed of a (001)-oriented ReO₃ layer 13, a (001)-orientedferroelectric layer 14 having a perovskite structure and an upperelectrode 15. The lower ReO₃ electrode 13 is extracted along a directionperpendicular to the drawing sheet. An insulating layer 18 made ofsilicon oxide or the like is formed to cover the ferroelectriccapacitor.

[0070] Desired portions of the insulating layer 18, MgO layer 12 andsilicon nitride layer 59 are removed by etching, to form contact holes.Then, a local wiring 19 connects the plug 49 exposed in the contact holewith the upper electrode 15. An insulating layer 50 is further formed tocover the local wiring 19. Through the insulating layer 50, an openingfor exposing the plug 49 on the other source/drain region 46 is formed.The other wiring 55 is formed, filling the opening.

[0071] The above-described constitutions around the ferroelectriccapacitor and around the transistor, which are shown in FIGS. 3A and 3B,respectively, are examples, and have no limitative meaning. Variousalternations and exchanges may be employed. Multi-layered wiringstructure can be formed by other publicly known techniques. As describedabove, the electronic device with the ferroelectric capacitor, forexample, a semiconductor integrated circuit device can be manufactured.

[0072] Although the present invention has been described along theembodiments, the present invention is not limited thereto. It will beobvious to those skilled in the art that various modifications,improvements and combinations can be made.

What we claim are:
 1. An electronic device comprising: a ReO₃ layerhaving a (001) orientation; and an oxide ferroelectric layer having aperovskite structure, said oxide ferroelectric layer being formed onsaid ReO₃ layer and having a (001) orientation.
 2. The electronic deviceaccording to claim 1, further comprising: a MgO layer having a (001)orientation, wherein said ReO₃ layer is formed on said MgO layer.
 3. Theelectronic device according to claim 2, further comprising: an amorphouslayer, wherein said MgO layer is formed on said amorphous layer.
 4. Theelectronic device according to claim 3, further comprising: an upperelectrode formed on said oxide ferroelectric layer.
 5. The electronicdevice according to claim 4, wherein said amorphous layer is formed ofan insulating layer, which is formed to cover a semiconductor elementformed on a semiconductor substrate, and a conductive plug is providedto electrically connect said semiconductor element, said conductive plugpenetrating through said insulating layer.
 6. The electronic deviceaccording to claim 5, wherein said ReO₃ layer is formed on saidinsulating layer and over said conductive plug.
 7. The electronic deviceaccording to claim 5, further comprising: an interlayer insulating layercovering said upper electrode; a plurality of apertures penetratingthrough said interlayer insulating layer and exposing said conductiveplug and said upper electrode; and a local wiring connecting saidconductive plug and said upper electrode via said apertures.
 8. Theelectronic device according to claim 2, wherein said MgO layer is asingle crystal MgO layer having a (001) plane.
 9. The electronic deviceaccording to claim 1, wherein said ReO₃ layer is added with metal otherthan Re.
 10. The electronic device according to claim 4, wherein saidupper electrode is formed of an IrO₂ layer, or a stack of an IrO₂ layerand a SrRuO₃ layer.
 11. A method of manufacturing an electronic device,comprising the steps of: (a) preparing a ReO₃ layer having a (001)orientation; and (b) forming an oxide ferroelectric layer having aperovskite structure and a (001) orientation, on said ReO₃ layer. 12.The method of manufacturing an electronic device according to claim 11,wherein said step(a) deposits said ReO₃ layer on a single crystal MgOlayer having the (001) orientation.
 13. The method of manufacturing anelectronic device according to claim 11, wherein said step (a) includesthe steps of: (a-1) preparing a MgO layer having a (001) orientation;and (a-2) forming said ReO₃ layer having a (001) orientation on said MgOlayer.
 14. The method of manufacturing an electronic device according toclaim 13, wherein said step (a-1) includes the steps of: (a-1-1)preparing an amorphous layer; and (a-1-2) forming said MgO layer havinga (001) orientation on said amorphous layer.
 15. The method ofmanufacturing an electronic device according to claim 14, wherein atleast one of said steps (a-1-2), (a-2) and (b) is done by metalorganicchemical vapor deposition (MOCVD).
 16. The method of manufacturing anelectronic device according to claim 15, wherein all of said steps(a-1-2), (a-2) and (b) are done by MOCVD.
 17. The method ofmanufacturing an electronic device according to claim 15, wherein saidMOCVD is executed at a substrate temperature of 620° C. or lower. 18.The method of manufacturing an electronic device according to claim 15,wherein said MOCVD uses, as organometal raw material, adipivaloilmethanate (DPM) compound of metal or an iso-proxy (i-PrO)compound of metal.
 19. The method of manufacturing an electronic deviceaccording to claim 14, wherein at least one of said steps (a-1-2), (a-2)and (b) is done by sputtering.
 20. The method of manufacturing anelectronic device according to claim 11, further comprising the step of:(c) forming at least one upper electrode layer on said oxideferroelectric layer.